Louis Charles Breguet (January 2, 1880 in Paris - May 4, 1955 in Saint-Germain-en-Laye, France) was a French aircraft designer and builder, one of the early aviation pioneers.

In 1902, Louis married the daughter of painter Girardet, Nelly Henriette Julia Girardet, who owned a villa in Houlgate. Together they had five children and the couple later bought the villa Le Clos de Royan which Louis renamed Villa Bréguet. There he entertained people of the world of aviation.

In 1905, with his brother Jacques, and under the guidance of Charles Richet, he began work on a gyroplane (the forerunner of the helicopter) with flexible wings. It achieved the first ascent of a vertical flight aircraft with a pilot in 1907. His first aircraft, which he built in 1909, set a speed record in 1911 for its 10 kilometre (6.2 mile) flight. Also that year, he founded the Société Anonyme des Ateliers d'Aviation Louis Breguet. In 1912, Breguet constructed his first hydroplane.

He is especially known for his development of reconnaissance aircraft used by the French in World War I and through the 1920s. One of the pioneers in the construction of metal aircraft, the Breguet 14 day bomber, perhaps the most famous French warplane of all time, was made almost entirely of aluminium. As well as the French, sixteen squadrons of the American Expeditionary Force also used it. A plane of this type has a major role in the plot of the 1927 thriller So Disdained by Neville Shute.

In 1919, he founded the Compagnie des Messageries Aeriennes, which evolved into Air France.

Over the years, his aircraft set several records. A Breguet plane made the first nonstop crossing of the South Atlantic in 1927. Another made a 4,500 mile (7,250 km) flight across the Atlantic Ocean in 1933, the longest nonstop Atlantic flight up to that time.

He returned to his work on the gyroplane in 1935. Created with co-designer René Dorand, the craft, called the Gyroplane Laboratoire, flew by a combination of blade flapping and feathering. On December 22, 1935, it established a speed record of 67 mph (108 km/h). It was the first to demonstrate speed as well as good control characteristics. The next year, it set an altitude record of 517 feet (158 m).

Breguet remained an important manufacturer of aircraft during World War II and afterwards developed commercial transports. Breguet’s range equation, for determining aircraft range, is also named after him.

Brequet, as helmsmen of his 8 Metre yacht Namousa, won a bronze medal in sailing during the 1924 Summer Olympics.

He died of a heart attack in 1955 at Saint-Germain-en-Laye.